Description

MicroSquirt with 30″ Harness is an entry-level, fully assembled ECU and universal 30″ pigtail with varied applications targeting power sports, single cylinder all the way up to 8 cylinders with up to 2 fuel and 4 spark outputs. Over 40 different ignition modes are supported from mainstream applications like GM LS1, Ford Zetec, Bosch Motronic, and Chrysler Gen III Hemis to unusual modes like Renix Jeep and the Suzuki Swift GTI.

MicroSquirt transmission control free firmware allows you to use MicroSquirt with 30″ Harness to control a number of electronic automatic transmissions (gearboxes). It can work standalone or integrate with one of our ECU’s over canbus.

Is this just for motorcycles and other small engines, or can it be used in a car or truck?

The MicroSquirt can run regular automotive engines; it’s not just for powersports applications. It is possible to run this on a V8 in wasted spark, although it doesn’t have very much I/O to spare for extra functions when using four spark outputs.

I’ve heard some people say it has two spark outputs and some say four. What’s the deal?

It was originally designed for two spark outputs, but the MS2/Extra code allows you to use WLED and ALED outputs as additional spark outputs. You will need to add resistors in the wiring harness for using them with most coils.

Is it waterproof?

No, but you can make it waterproof with a bit of RTV silicone around the edge of the case.

Are there other versions of the MicroSquirt for other functions? Transmission control or the “IO Box”, for example?

These all use the same ECU, just running different code to change its function and use it as a transmission control unit or I/O expansion device. See MSExtra.com for details.

Could I use two MicroSquirts, one running the engine and one running the transmission?

Yes. They would link up over their CAN networks to look like a single unit to the tuning software.

Questions & Answers

The MicroSquirt can run fuel and ignition on a single cylinder no problem. Reverse engineering a stock map is a bit of a challenge. If the stock ECU puts out OBD2-type codes, you could try this method from Andy Whittle's How EFI Works channel on YouTube. The MS2/Extra setting up manual also covers how to put together a startup tune.

This unit would be capable of running a V8 with bank to bank fueling, wasted spark ignition, and at that point it would be close to the limits of available I/O. Stepping up to something in the MS3 family like an MS3Pro EVO would allow for fully sequential fuel and ignition control as well as control over the variable valve timing.

We do not have any experience with aircraft safety requirements, so you are responsible for any work required by your country to demonstrate aircraft safety. That said, the MicroSquirt can operate the engine if it does not use low impedance injectors and does not use a stepper IAC valve.

The Ford V6 is fairly straightforward. You will need a QuadSpark ignition module if running the stock coil.

An MS2 V3.57 or V3.0 would be a better choice for the TBI. We do not recommend MicroSquirt on GM TBI applications as its injector drivers cannot handle the current that the very low resistance TBI injectors use without current limiting resistors (which slow down their opening times) and does not have an output for the stepper IAC valve. The MS2 can run both of these out of the box and is a better fit for TBI applications.

This unit will have full control over fuel and ignition on this car. Stepping up to an MS3 will give you more advanced boost control, traction control, individual cylinder tuning, and other high end features.

The MicroSquirt has only two injector outputs. Normally on a 3 cylinder 2 stroke, the system would use one coil that sparks all three cylinders at once, and the MicroSquirt software is set up to do this. It does not currently support 2 separate coils on a 3 cylinder unless they are triggered at the same time.

This may be an odd fire motor, but it's not a particularly odd application - we have a number of customers using this ECU on Harley V-twins. It has two fuel and two ignition outputs, and supports many motorcycle crank trigger patterns natively.

We currently do not have an easy way of controlling direct injection systems - they run at around 50 to 100 volts, and need special voltage and current control circuitry. There have been some experimental installs with systems in the MS3 family using third party direct injector driver circuits, but this is highly experimental and not something documented well enough for others to duplicate.

This would only be street legal if installed in a vehicle that predates emissions controls.

You could use one MicroSquirt to control the engine and one MicroSquirt to control a 4R70W or similar transmission. If running stock Ford coil packs, you will need to use our QuadSpark ignition module as well.

It has a 2 step rev limiter - you can use the flex fuel or analog inputs to trigger this function. Full on rally style anti lag would require stepping up to something in the MS3 line as this is difficult to do without fully sequential injection.

That can work as long as you use current limiting resistors - the TBI injectors draw a lot of current. You can use GM air temperature and coolant temperature sensors and a GM style MAP sensor with this ECU.

You will need air and coolant (or cylinder head) temperature sensors, an RPM input, and a MAP or throttle position sensor. A wideband O2 will make the tuning part of the build a lot easier. I'd typically recommend sourcing the fuel delivery hardware (injectors, throttle body, and fuel pump) off a fuel injected motorcycle or scooter for small engine builds.

Note that MicroSquirt can run the Honda ignition without an EDIS4 module, or even run a distributorless ignition triggered off the factory Honda distributor pickup. EDIS is rather unnecessary at this point - and may stick you with a rev limiter intended for a Ford 1.9 CVH engine. For more details, see the Nippondenso CAS notes in the MicroSquirt Hardware Manual.

Yes, you can trigger it from a distributor, no problem. Some of the earliest MicroSquirt installs were on engines with distributors and no trigger wheel (other than what was in the distributor, of course), before they were even released to the general public. You will also need air and coolant temperature sensors, and a wideband O2 sensor will make tuning it a lot easier.

The MicroSquirt is basically a scaled down MS2. The PWM current limiting for low impedance injectors and the stepper IAC outputs are the main features that didn't make the cut. The overall I/O is somewhat more than a standard MS2, but you can add somewhat more I/O to an MS2 if you add enough mods to it. A MicroSquirt, by contrast, is a standard package that is only built one way.

Yes, as long as you use a thermistor type cylinder head temperature. The MicroSquirt currently does not support thermocouples for engine temperature, but there are a number of suitable thermistor type CHT sensors out there.

MicroSquirt Module is a credit card sized engine management board! This board packs all the features of the MicroSquirt into a 3.5" x 2.4" PCB, with all components installed. This tiny ECU opens up unprecedented possibilities - there's never been a stand...

MegaSquirt-I CPU; Motorola 68HC908 microprocessor loaded with standard B&G MegaSquirt-I firmware version 3.0. This part is discontinued and available while supplies last.
For use with any MegaSquirt PCB version 1, 2.2, 3.0, 3.57...